Some 29,376 people died from terrorism in 2015, down 3,389 on the previous year and the first fall since 2010, according to the Global Terrorism Index published by the Institute for Economics and Peace.

This fall was thanks largely to 5,556 fewer deaths in Iraq and Nigeria — a reduction of one third since 2014 — as military operations weakened IS and Boko Haram.

However, both groups also expanded their geographical reach last year. Boko Haram killed more people in Niger, Cameroon and Chad than in 2015.

IS affiliates meanwhile launched attacks in 28 countries in 2015, 15 more than in 2014.

Deaths in OECD countries increased from 77 in 2014 to 577 the following year. More than half of them have IS connections.

“The attacks by IS in Paris, Brussels and in Turkey’s capital Ankara were amongst the most devastating in the history of these countries. This, therefore, reflects a disturbing return of the transnational group-based terrorism more associated with al-Qaeda before and immediately after September 11,” the report said.